Been running it for about a week or two now. It's nice and neat. I dislike most of it's default options, but that's just me and I used Synaptic to pull in the ones I wanted. Hardware support on the laptop was dodgy, at best, but that's hardly a Ubuntu specific problem. It's more like a Linux wide issue with ACPI, "smart" batteries and the like.
Ubuntu backports is a nice addition though. I got myself the new Bluefish, the new kernel and a bunch of other goodies (a recent xfce! *drool*) from there. No problems at all. Overall, Ubuntu makes a nice alternative to the usual Fedora, Mandrake, Suse distros and it seems to have most of the basic stuff done right. And trying out Gnome for the first time since I abandoned it in disgust four years ago (1.4) was educational.